1. Field of the Invention
This invention relates to video synthesizers and, more particularly, to video synthesizers for producing video signals derived as a combination of an input image signal and a function generator.
2. Description of the Prior Art
The use of video synthesizers is a well established and accepted technique in the television industry. Video synthesizers are commercially available, but as a practical matter are sufficiently expensive that they are available only to a very limited market. Prior art synthesizers are generally designed to generate predetermined video patterns, and as a general proposition a wide range of patterns can be synthesized. However, for a hard-wired synthesizer, the number of available video functions or patterns is necessarily limited. More complex synthesizers utilize computer control, which provides a great deal of flexibility but at a concomitant considerable cost. Not only is the computer unit itself expensive, but the required software necessary for programming the unit is very expensive.
There is a great portion of the television industry which could benefit from a relatively low cost video synthesizer having a degree of programming flexibility, which segment of the market is presently excluded for economic reasons from use of higher priced synthesizers. For example, industrial TV studios, educational institutions, and the like have a great need in producing television programming for aids in providing animated presentations, moving graphics, and the like. Heretofore, such presentations have been available only through the use of the much higher cost synthesizer equipment, or extensive artwork such as is used in conventional animated television productions. What has been long needed in this area, and what is provided by this invention is means for providing the television user with a medium whereby a rather limited amount of artwork can be combined with a relatively inexpensive video synthesizer to provide a great flexibility in producing television displays characterized by moving illustrations, changing color, etc.